Scientists have discovered the reason why human hair loses color and turns gray as we age, reported New York Post. According to a team of scientists, melanocyte stem cells get stuck inside the hair follicle and are unable to produce pigment.
The results were published Wednesday in the peer-reviewed scientific journal Nature. For the study, scientists spent two years tracking individual cells in mice’s fur to determine how hair turns gray and looked closely at melanocyte stem cells known to control hair color. They used special scans and lab techniques to study the cellular aging process.
They discovered that the pigment-producing part of a stem cell would change as the mice matured. “The melanocyte stem cell system fails earlier than other adult stem cell populations, leading to graying hair in most humans and mice,” the study says.
As hair ages, falls out, and regrows, melanocyte stem cells get stuck in a part of the hair follicle called the hair follicle bulge. When the stem cells stop moving around the follicle and attach themselves, they fail to mature into full-fledged melanocytes. The hair then turns gray, white or silver because no pigment is produced.
Mayumi Ito, the study’s author and a professor of dermatology at New York University’s Grossman School of Medicine, said, “This is a really big step forward in understanding why we go gray.”
He explained: “It is the loss of chameleon-like function in melanocyte stem cells that may be responsible for graying and loss of hair color.”
The researchers also suggested that if their findings prove true for humans, they could open up a potential way to reverse or prevent gray hair.
The study’s principal investigator, Qi Sun, said: “The new mechanisms raise the possibility that the same fixed positioning of melanocyte stem cells may exist in humans. If so, it presents a potential pathway to reverse or prevent graying in human hair by helping blocked cells move between compartments of the developing hair follicle again.